01 - In a large mixing bowl, whisk together the olive oil, lemon juice, Greek yogurt, minced garlic, red wine vinegar, dried oregano, dried thyme, salt, black pepper, and lemon zest until well combined and emulsified.
02 - Add the cubed chicken to the marinade, tossing to coat each piece thoroughly. Cover the bowl with plastic wrap and refrigerate for a minimum of 1 hour, or up to 8 hours for deeper flavor penetration.
03 - If using wooden skewers, submerge them in water for at least 30 minutes to prevent burning on the grill.
04 - Thread the marinated chicken pieces onto skewers, alternating with chunks of red onion, red bell pepper, yellow bell pepper, and zucchini rounds, distributing the ingredients evenly across each skewer.
05 - Preheat an outdoor grill or grill pan to medium-high heat. Lightly oil the grates to prevent sticking.
06 - Place the skewers on the grill and cook for 6 to 8 minutes per side, turning once, until the chicken is cooked through to an internal temperature of 165°F and has developed a light char on the edges.
07 - Remove the kabobs from the grill and serve immediately with lemon wedges, a sprinkle of fresh parsley, and tzatziki sauce on the side.